Process for treating synthetic benzine products from hydrogen and the oxides of carbon



Sept. 6, 1938. F. FISCHER ET AL 2,128,994

PROCESS FOR TREATING SYNTHETIC BENZINE PRODUCTS FROM HYDROGEN AND THE OXIDES OF CARBON Filed July l0, 1935 imiliurnmlilililil'l Mi www Patented Sept. 6, 1938 UNITED sTATEs vPATENT oFFl'cE PROCESS FOR TREATING SYNTHETIC BEN- ZINE PRODUCTS FROM HYDROGEN AND THE OXIDES OF CARBON Application July 10,

1935, serial' No. 30,624

In Germany J'uly 19, 1934 2 Claims.

It is known that in the production of benzine by synthesis from carbon monoxide and hydrogen at normal pressure, as suggested for instance in Patent No. 1,746,464, gaseous and liquid ali- 5 phatic hydrocarbons are obtained having highly varying boiling lpoints and comprising in addition to mono-oleflnes, mainly saturated hydrocarbons such as gasol, light benzine, heavy benzine, illuminating oil, heating oil and solid paraflln, wherein "gasoP designates a mixture of .gaseous saturated and unsaturated aliphatic hydrocarbons and more particularly a mixture of methane and ethane with their higher gaseous homologs. It is inherent in the nature of these l5 products that from the benzines as obtained only the benzine which has a boiling point 'up to about 100 C. satisfies present day requirements in resistance to detonation, even when by se-` lecting the conditions of production, the composition of the gases, and the nature of the catalyst are so determined that there are as many monoolenes in the benzine as possible. Onthe other hand it has been found ("Brennstoffchemie vol.

15 (1934) page 229), that particularly valuable lubricating oils can be produced by condensation from the mono-oleflnes of the fraction between 100 and 250 C. and over. In order to ,convert as far as possible the whole products of the synthesis of benzine into the particularly desirable substances, namely, anti-detonating benzine and valuable lubricating oils, it has been found particularly advantageous to proceed as follows;-

First of ail light benz-ine which boils up to about v100 C. is removed from the liquid raw product obtained at normal pressure by the synthesis of benzine from hydrogen and the oxidesv of carbon. Thereupon solid paramn is removed from the higher-boiling benzine veither by disortillation or in any other manner, for example by z`cooling or by solution or by fractional distillation. Lubricating oils having a low solidiilcation `,pointvare obtained'by condensation trom the oleilnes contained in the higher boiling constituents either directly or after dilution or after an enriching operation. The production -of the lubricating oils. in this state is of importance, because before cracking no other constituents. such as aromatic hydrocarbons, are present. Due to the absence of aromatic hydrocarbons, lubricating oils are obtained in this, manner, the viscosity of 'which is dependentupon the temperature in a rather small'measure. Thereupon distillation. is advantageously carried out under vvacuum during `which the lubricating oils re-l main behind. The distillate is subjected to a cracking process which can produce benzine that is resistant to detonation. The soft solid paraffin removed, as mentioned above, from the higher-boiling benzine before the production of the lubricating oil, may be admixed with the distillate separated from the lubricating oils and may thusbe subjected to the same cracking process. The light benzine. hereinbefore referred to and the cracked benzineproduced may then be mixed in any suitable proportions or may be used separately, according to which kinds of benzine are desired. By this method the entire raw liquid products resulting from the 'synthesis of benzine canv be treated to produce benzine A resistant to detonation and valuable lubricating oils, in addition to a small'residue of oil resulting from the cracking operation. This method produces primarily a light benzine whose resistance to detonation is equal to that of Baku benzine, while furthermore cracked benzines are obtained whose octane number is over 70, and finally the combined operations described produce valuable lubricating oils having viscosity indices lying between 1.6 and 2.6, whose absolute viscosity is merely a question of concentrating by distillation.

In carrying the invention into effect according to' one method 100 kg. of a raw product are taken, produced at a reaction temperature of about 200 C. from water gas at normal pres- -sure by the use of a, catalyst consisting of cobalt metal and zinc oxide. The water-clear product has a speciiic gravity of 0.72 at 20 C., and consists up to about 45% of olene hydrocarbons. At first the mixture is distilled at normal pres- Asure until the temperature of the vapor is 125, C. By this means 42 kg. of lightbenzine isA obtained which has a specific gravity of 0,67 at 20 C., and has an oleflne content of lby volume. The octane number determined by the C. F. R. motor method is 65. The distillation of the raw product is then continued until the temperature of the vapor is 250 distillate being secured. The residue of distillation amounting to 21 kg., by reason of the high content ot soft parailin, solidlfles to produce crude parafiln.v l

The heavy benzine distillate of a specific gravity of 0.74 has an olene content of 40%, and is treated-in the manner hereinafter described to produce, lubricating oil. v

The product is rst 'mixed in an iron polymerization vessel provided with a good stirrer, with 1 kg. ofcommercial anhydrous aluminium C., 37 kg. of a heavy benzine.

chloride at `room temperature, whereupon the reaction temperature is raised within a period of 2 hours to 120 C. At this temperature the mixture is Well stirred for afurther six hours, and then allowed tov cool. The reaction product is as the result separated into two layers, the lower of which consists of an addition-compound of aluminium chloride which can be used as catalyst for further conversions. To secure lubricating oil the upper layer of oil is first purified with about 1% of fullers earth and then is subjected to distillation. The distillation is carried out until the vapor temperature is 250 C. at normal pressure, and then is continued under vacuum at 15 mm. of mercury, until the vapor temperature is 200 C. This produces 25 kg. of a distillate, and as residue 10.5 kg. of a lubricating oil having the following properties:

Specic gravity at 20 C. 0.840; viscosity 20.8 Engler at 20 C. and l1.66 Engler at 50 C; Viscosity index 1.90; solidilcation points 36 C. The distillate contains practically no olene hydrocarbons, and is cracked for conversion into anti-knock benzine together with soft paran which is left in distilling the raw product which serves as raw material for the process.

The residue which contains soft paran to the extent of 21 vkg. and the distillate poor in olenes originating from the manufacture of lubricating oil to the extent of 25 kg. produce during combined cracking 39 kg. of a cracked benzine Whose octane number is 75.

Thus by treating the rawproduct of synthetic benzine by the process according to the present inventionf42% by weight of primary benzine is producedl having octane number 65, 39% by weight of cracked benzine, havingoctane number '75, and 10.5% by Weight of valuable lubricating oil with a viscosity index of 1.90.

The process of the invention is diagrammatically indicated by way of example in the accompanying drawing. As illustrated in the drawing the raw product which is obtained in the synthesis of benzine from carbon monoxide and hydrogen at normal pressure is rst distilled off in the still a up to a temperature of 125 C. of the vapors passing 01T. These vapors provide during condensation a light benzine b which is sufficiently resistant to detonation.v Thereupon the residue in the still a is further distilled until a vapor temperature of 250 C. is reached. The heavy benzines produced, after condensation pass into the Apolymerization vessel c which is provided with a stirring device d. The raw product obtained during polymerization is carried over into the still and thendistilled. A lubricating oil remains which is drawn oi at y While the distillate passes into the cracking apparatus h. Furthermore the soft paraffins remaining behind in the still a, after the second distillation are passed into'the cracking apparatus h. The remaining cracked benzine is drawn oi at y' while the uncondensed cracking gases leave at k.

Various changes may be made in the details disclosed in the foregoing specification Without departing from the'invention or `sacricing the advantages thereof.

We claim:

1. The method of converting into more valuable products synthetic benzine obtained by reacting hydrogen with carbon monoxide in the presenceof a catalyst at elevated temperature under about 4atmospheric pressure, comprising the steps of subjecting the product of the reaction of hydrogen with carbon monoxide, from which have been separated the fraction boiling below C. and the paran capable of solidication, which was formed in said reaction, to polymerization in the presence of a. polymerization catalyst, of thereafter distilling' the polymerization product first at ordinary pressure and then in vacuo for the recoveryof a residue adapted for use as a lubricant and of a further quantity of low-boiling benzine,` of admixing said parailn to this low-boiling benzine and of cracking said mixture for the recovery of knock-proof benzine.

2. The process of producing knock-proof benzine and lubricating oil, which comprises passing watergas at about 200 C. and at about atmospheric pressure in contact with a hydrogenation catalyst, subjecting the reaction products to distillation at a temperature up to about 125 C., separating the distillate, continuing distiilation up to about 250 C., heating the second distillate, after separation from the paranic residue obtained, under stirring in the presence oi a polymerization catalyst to about C., purifying the oil layer thereby obtained, distilling same at ordinary pressure up to 250 C., and continuing the distillation up to 200 C. under a high vacuum for the recovery'of a third distillate and of a residue which is adapted for use as a lubricant,

and cracking said third distillate together with said paranic residue to recover knock-proof benzine.

FRANZ FISCHER. HERBERT KOCH. 

